* Implement IApplicationFunctions & IQueryService commands
- Fix some nits in `IApplicationFunctions`
- Implement `QueryApplicationPlayStatistics` and `QueryApplicationPlayStatisticsByUid` checked by RE.
- Implement `QueryApplicationPlayStatisticsForSystem` and `QueryApplicationPlayStatisticsByUserAccountIdForSystem` checked by RE.
- Implement `QueryPlayStatisticsManager` to get/set played games statistics. We currently don't store any statistics because it's handled by qlaunch (or maybe am service?) on Switch.
We can add support later if games use returned statistics for something.
* Fix reviews
* Refactoring HOS folder structure
Refactoring HOS folder structure:
- Added some subfolders when needed (Following structure decided in private).
- Added some `Types` folders when needed.
- Little cleanup here and there.
- Add services placeholders for every HOS services (close#766 and #753).
* Remove Types namespaces
